Refrigerating apparatus



Oct. 27, 1936. 1 A. PHILIPP REFRIGERATING APPARATUS Original Filed Sept. 9, 1932 Sheets-Sheet l rlllllllllllllll l.IIIlllllllllllllllmdlllllllllllll MSE.

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ATTORNEY.

Oct. 27, 1936. .A. PHILIPP REFRIGERATING APPARATUS 2 Sheets-Sheet 2 Original Filed Sept. 9, 1932 mww INVENTOR, mr/MNM v a. Pff/MMD ATTORNEY.

l Patented Oct. 27, 1936 d UNITED STATES REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich., assigner to Kelvlnator Corporation, Detroit, Mich., a corporation of Michigan Applicationv September 9, 1932, Serial No. 632,323 Renewed September 29, 1934 1 Claim.

ratus, and more particularly to refrigerant evaporators for use in such apparatus.

In providing'refrigeration for ice creams and other frozen edibles by a refrigerant evaporator at temperatures below the thawing point of such articles, considerable difficulties have been experienced in maintaining uniform temperatures within certain predetermined ranges. These conditions were encountered due to the superheating of the liquid refrigerant contained in the evaporator by failure of the initiation of ebullition at the proper times. This condition impeded the proper transfer of heat to the refrigerant contained in the evaporator and prevented uniform temperatures within certain ranges, and under certain conditions prevented the maintenance of suiciently low enough temperatures for the proper refrigeration of the stored food articles. In addition, it was found difficult to maintain uniform temperatures throughout the entire evaporator or cooling element.

' Accordingly, it is one of the objects of my invention to provide for initiating ebullition in a refrigerant evaporator by injecting expanded refrigerant into the liquid refrigerant contained in said evaporator at pressures greater than those normally existing therein to increase the heat transfer from the medium surrounding the evaporator to the refrigerant contained therein.

Another object ofthe invention is to provide uniform temperatures within certain ranges in a food storage compartment by a refrigerant evaporator by positively circulating and initiating the ebullition of refrigerant contained therein.

Another object is to promote the circulation and ebullition of refrigerant throughout a refrigerant evaporator to insure substantially uniform temperatures throughout the evaporator.

Another object is to provide for the ready return of oil from the evaporator to the condensing unit associated therewith.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a View shown partly diagrammatically and partly in cross section of a refrigerating apparatus embodying features of my invention;

Fig. 2 is a top plan view partly in cross section and partly in elevation of a portion of the apparatus shown in Fig. 1;

Fig. 3 is an enlarged view in cross section of the nozzle shown in Fig. 1;

Fig. 4 is an enlarged view shown in cross section of the valve mechanism shown in Fig. 1;

Fig. 5 is a View shown partly in cross section and partly in elevation of a modified form of re- (Cl. 62-l26) 'I'his inventionrelates to refrigerating appa-` frigerating apparatus embodying features of my invention; and

Fig. 6 is a top plan view shown partly in cross section and partly in elevation of a portion of the apparatus shown in Fig. 5.

Referring to the drawings, the numeral 20 designates in general a cabinet of the type suitable for storing ice creams, frozen package goods and the like to be kept at low temperatures. The cabinet is constructed of insulated walls 22, which cooperate to form a compartment 23. Within the compartment 23 is disposed a refrigerant cooling element 25. A refrigerant condensingor circulating element 21 is operatively associated with the cooling element 25.

The cooling element 25 comprises in general a. header 32 adapted to contain a quantity of liquid refrigerant. The header is preferably of tubular formation and is provided on one end thereof with a valve plate 35 clamped between a cover plate 36 and an end ring 38, which is preferably welded to the tubular wall of the header 32. Depending from the lowermost portion of the header is a standpipe or refrigerant accumulator 39, which is in open communication with the interior of the header 32. A refrigerant expansion coil or conduit 40 is connected on one end thereof to the lower end of the accumulator and on the other end thereof to the header 32 above the level of liquid refrigerant therein. Suitable float valve mechanism 42 is provided within the header for the purpose of maintaining a substantially constant level of liquid refrigerant therein. The float valve mechanism includes a float 44 and valve 46, which cooperates with valve seat 41 to control the passage of liquid refrigerantffrom the high pressure side of the condensing element to the low pressure side or cooling element. The refrigerant header and accumulator are enclosed within a thin metallic casing 50.

The expansion conduit 40 is helically wound around and in good contact with a tank or sleeve member 52. The tank or sleeve member 52 is arranged to accommodate one or more open top food containers 54. The cabinet is provided with removable covers or lids 55 for gaining access to said containers.

The refrigerant condensing element 2l comprises in general a compressor 60, condenser 62, motor 63 for operating the compressor, and liquid 'refrigerant receiver 64. The compressor withdraws gaseous refrigerant from the cooling or evaporating element through a vapor conduit 6l, compresses the gaseous refrigerant and delivers it to the condenser wherein it is liquefied and from which it is delivered to the liquid refrigerant receiver. Liquid refrigerant is delivered to the cooling element through a supply conduit 10. An automatic switch 1I is provided for controlling the operation of the motor in response to changes in pressures in the vapor conduit 61 in the well known manner.

Suitable connections 12 and 14 are provided in the cover plate 88 to which the conduits 61 and 10 are connected, respectively. Liquid refrigerant passes from supply conduit 10 to the connection 14 and when the float valve is open the liquid refrigerant passes through the oritlced valve seat 41 into pasage 80, which communicates with a conduit 82. Liquid refrigerant passes through the conduit 82, whence it is injected into the inlet end of the expansion conduit 40 by means of an injector or nozzle 85 in a manner about to be described.

During periods when the float valve is open liquid refrigerant passes through conduit 82 and injector 85 into conduit 40. Since the accumulator 39 is in open communication with the header and the conduit 40 is in open communication with the accumulator, the level of liquid refrigerant in the expansion conduit 40 will normally be the same as in the header. When refrigerant is being injected into the expansion conduit 40, a portion thereof will flow through the outlet or upper end of said conduit and into the header until the float rises s ufllciently to close the float valve.

From the foregoing it will be apparent that the large column of liquid refrigerant in the header and accumulator will cause evaporated refrigerant in the conduit to pass through the outlet end of the conduit 40 and into the gas space in the header, due to the resistance offered by said large body of liquid. Under some circumstances it has been found that the evaporation of refrigerant has been so great in the conduit as to pick up liquid refrigerant and deliver it to the header whence it descends into the accumulator to be recirculated.

In order to promote and to initiate the ebullition as well as the circulation of liquid refrigerant through the expansion conduit 40, the injector 85 has been provided. This prevents the superheating of the liquid refrigerantin the expansion conduit 40, and tends to keep uniform temperatures throughout the entire evaporator. The injector 85 is formed by restricting the outlet end of the conduit 82. The restricted end is disposed part way into a fitting S to which the conduit 40 is connected. A recessed casting 92 is provided as a mounting and housing for the injector. The casting on its upper part is secured to the accumulator, preferably by welding. The injector is adapted to inject expanded refrigerant into the conduit 40. During periods when the float valve is open, the refrigerant leaving the high pressure side of the system and entering the low pressure side through the oriced valve seat 41 becomes expanded (partly liquid and partly gas). The expanded refrigerant is received in the conduit 82 at pressures somewhat greater than those normally existing in the conduit 40. This high pressure expanded refrigerant leaves the injector and enters the liquid refrigerant in the conduit 40 where the pressure is lower. Consequently, the injector provides a means of positively circulating liquid refrigerant in the cooling element. It will also be noted that the gaseous part of the injected refrigerant immediately initiates the ebullition of refrigerant in the conduit 40 upon its admission thereto. Also, the gaseous part of the injected refrigerant, in addition to starting ebullition in the expansion conduit, promotes ebullition throughout its passage therethrough.

By positively circulating, initiating and promoting ebullition in the cooling element, the oil pumped thereinto by the compressor is readily returned to the compressor through the vapor conduit by reason of its entrainment with the evaporated refrigerant. Y

In Figs. 5 and 6 is shown another form of the invention in which refrigerant is also supplied to the circulating system in a manner to circulate and to initiate the ebullition of the refrigerant therein. In this instance a high side float mechanism indicated diagrammatically at |00 is employed, instead of a low side iioat mechanism, to control the quantity of refrigerant supplied to the system. The accumulator |02 is disposed in one corner of the cabinet and may be suitably secured to the sleeve |03, such as by straps |05. The accumulator |02 is in communication adjacent the top with the compressor |01 which withdraws gaseous refrigerant therefrom through conduit |08.

Adjacent the bottom of the accumulator |02, a nozzle or injector |09, similar to that previously described, extends therethrough and in alignment with the inlet end ||0 of the conduit i i Thus, as the high side float mechanism |00 functions to allow refrigerant to be supplied to the system, the refrigerant passes through the nozzle |09 at high velocity and entering the conduit i in the same manner as refrigerant enters the conduit 40.

From the foregoing description it will be apparent that I have provided a new and efficient refrigerant evaporator. With this evaporator, the liquid refrigerant therein is influenced to begin vaporizing immediately upon entrance of the expanded refrigerant into the lowermost coil of the expansion conduit thus obtaining a more eiiicient absorption of heat from the freezing compartment.

What I claim as my invention is:

A refrigerating apparatus comprising a re frigerant standpipe having a relatively large cross sectional area, a refrigerant evaporating element consisting of only a single conduit having a relatively small cross sectional area and having its outlet end connected to the refrigerant gas space above the liquid refrigerant in said standpipe and its inlet end connected to the lower part of said standpipe, an expansion device for controlling the flow of liquid refrigerant to said evaporating element and for causing a substantial quantity of liquid refrigerant to accumulate in said standpipe. said evaporating element being arranged to circulate refrigerant upwardly from said inlet to said outlet, and means for circulating refrigerant upwardly comprising liquid refrigerant injector means positioned in the liquid part of said evaporating element in the direction oi' flow therethrough for picking upjliquid refrigerant in said standpipe and causing it to circulate through said evaporating clement.

LAWRENCE A. PHIHPP. 

